- Add POST /v1/billing/portal endpoint for customer portal access
- Add GET /v1/billing/recover endpoint for API key recovery
- Implement getKeyByEmail() and getCustomerIdByEmail() service functions
- Add comprehensive test coverage for new endpoints and services
- Create dedicated recovery page at /recovery.html with forms
- Add 'Lost your API key?' link on landing page near pricing
- Update OpenAPI documentation for new endpoints
- Return masked API keys for security (snap_xxxx...xxxx format)
- Log full keys for manual email sending (email service TBD)
- Include proper error handling and input validation
